1. Field
The disclosure relates to an electromotive vehicle including a transmission device and, more particularly, to control over braking force that acts on a vehicle at the time of an upshift.
2. Description of Related Art
In an electromotive vehicle that uses a motor generator as a drive source, a transmission device may be provided in a power transmission path between the drive source and a drive wheel. As such an electromotive vehicle, for example, Japanese Patent Application Publication No. 2009-165289 (JP 2009-165289 A) describes a control apparatus for a vehicle. When a regeneration request has been issued at the time of an upshift, the control apparatus outputs torque such that the torque is gradually changed from a negative torque that is output from the motor generator at the end of the shift to a target negative torque and sets the output gradient of the torque in response to a time that is taken from the regeneration request to the end of the shift.
For example, when a low speed-side speed ratio is established in the transmission device, if the rotation speed of the motor generator reaches an upper limit value that takes durability into consideration, the rotation speed of an input shaft of the transmission device may be decreased by upshifting the speed ratio of the transmission device. In this case, decelerating force of the vehicle may change as a result of upshifting the speed ratio of the transmission device. For such inconvenience, it is conceivable to prevent or reduce a change in the decelerating force of the vehicle by changing the negative torque that is output from the motor generator as in the case of the control apparatus for a vehicle, described in JP 2009-165289 A. However, if the input electric power of a battery is limited, it may be difficult to generate a negative torque that is required to prevent or reduce the change in decelerating force. For this reason, when decelerating force changes as a result of an upshift, the drivability of the vehicle may deteriorate.